The series is set in a future age of interstellar travel and follows the exploits of a group of renegades and convicted criminals. Gareth Thomas played the titular character Roj Blake, a political dissident who is arrested, tried and convicted on false charges, and then deported from Earth to a prison planet. He and two fellow prisoners, treated as expendable, are sent to board and investigate an abandoned alien spacecraft. They get the ship working, commandeer it, rescue two more prisoners, and are joined by an alien guerrilla with telepathic abilities. In their attempts to stay ahead of their enemies and inspire others to rebel, they encounter a wide variety of cultures on different planets, and are forced to confront human and alien threats. The group conducts a campaign against the totalitarian Terran Federation until an intergalactic war occurs. Blake disappears and Kerr Avon then leads the group. When their spacecraft is destroyed and one group member dies, they commandeer an inferior craft and a base on a distant planet, from which they continue their campaign. In the final episode Avon finds Blake and, suspecting him of betraying the group, kills him. The group is then shot by Federation guards, who surround Avon in the final scene.